Chemist, you misunderstand the eBay bidding system. When you are outbid by $1, that amount is NOT (likely) what the person bid; it is the next bid increment above yours.
In other words, if you are the second highest bidder at $45 and the winner bid $100, his final bid will show as $46, a dollar above yours. You have no way of knowing his actual maximum.
Also, I recommend that you simply decide your max when you set your snipe, rather than going back later and changing it as the price goes up. One of the points of sniping is to stay away from the bidding frenzy. By deciding your true maax up front, you will avoid spending more than you intended.